Methods and apparatus for sealing variable area fan nozzles of jet engines

ABSTRACT

Methods and apparatus for sealing variable area fan nozzles of jet engines are disclosed. An apparatus in accordance with the teachings of this disclosure includes a frame and a seal to be coupled to the frame. The seal to enclose petals of a variable area fan nozzle to substantially prevent airflow between the petals.

RELATED APPLICATION

This patent arises from a continuation of U.S. application Ser. No.13/665,188, titled “Methods and Apparatus for Sealing Variable Area FanNozzles of Jet Engines,” and filed Oct. 31, 2012, which is herebyincorporated by this reference in its entirety.

FIELD OF THE DISCLOSURE

This patent relates to sealing variable area fan nozzles and, morespecifically, to methods and apparatus for sealing variable area fannozzles of jet engines.

BACKGROUND

Variable area fan nozzle (VAFN) actuation systems may be used inaerospace applications to adjust an operating point of a propulsionsystem to adapt to different flight conditions.

SUMMARY

An apparatus in accordance with the teachings of this disclosureincludes a frame and a seal to be coupled to the frame. The seal is toenclose petals of a variable area fan nozzle to substantially preventairflow between the petals.

An example aircraft variable area fan nozzle petal actuation system sealassembly includes a frame and a seal coupled to the frame tosubstantially enclose the variable area fan nozzle petal actuationsystem between the frame and seal.

An example method of sealing an aircraft variable area fan nozzle petalactuation system includes disposing the variable area fan nozzle petalactuation system within a seal assembly formed by a frame and a sealcoupled to the frame to enclose the variable area fan nozzle petalactuation system between the frame and seal.

The features, functions, and advantages that have been discussed can beachieved independently in various embodiments or may be combined in yetother embodiments further details of which can be seen with reference tothe following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example airplane including an example sealed variablearea fan nozzle in accordance with the teachings of this disclosure.

FIG. 2 depicts an example jet engine in accordance with the teachings ofthis disclosure.

FIG. 3 is a partial cutaway view depicting an example variable area fannozzle enclosed within an example seal assembly in accordance with theteachings of this disclosure.

FIGS. 4-9 depict different views of an example seal assembly inaccordance with the teachings of this disclosure.

FIG. 10 depicts an example frame that can be used to implement theexamples disclosed herein.

FIGS. 11 and 12 depict different views of an example seal that can beused to implement the examples disclosed herein.

DETAILED DESCRIPTION

Certain examples are shown in the above-identified figures and describedin detail below. In describing these examples, like or identicalreference numbers are used to identify the same or similar elements. Thefigures are not necessarily to scale and certain features and certainviews of the figures may be shown exaggerated in scale or in schematicfor clarity and/or conciseness. Additionally, several examples have beendescribed throughout this specification. Any features from any examplemay be included with, a replacement for, or otherwise combined withother features from other examples.

The examples disclosed herein relate to jet engines and/or aircraftsincluding such jet engines having sealed variable area fan nozzles(VAFN) that reduce the weight and/or increase the performance ofaircrafts. Specifically, the examples disclosed herein relate to sealedVAFN petal actuation systems that increase aircraft fuel efficiency bysealing and/or preventing air leaks through the petals of the VAFN.

In some examples, the example seal assemblies include a frame and asingle-piece seal that completely encloses the VAFN petal actuationsystem between the frame and the seal, thereby reducing the possibilityof leaks therethrough. The seal may be positioned and/or stretched ontothe frame in tension to ensure the example seal seals against the petals(e.g., eight petals) as the petals move relative to the core cowl and/orthe nozzle exhaust of the jet engine. In the regard, the seal assembly,that is, the frame and seal, and the VAFN petal actuation system may becorrespondingly shaped. In some examples, when the petals are in acontracted position, the example seal is in lesser tension and, when thepetals transition to an expanded position, the seal is under increasedtension. The seal may define pockets to accommodate and/or enable themovement of the petals. To substantially prevent the seal from wearingand/or being damaged when moving relative to and/or rubbing against theframe, the frame may include urethane and/or other materials thatminimize such wear.

The frame may be used to support, secure and/or couple the seal, petalhinges, sensors and/or systems of the VAFN. The sensors (e.g., proximitysensors) may be used to identify the position of the system, the petals,etc. In some examples, to seal, couple, retain and/or secure the sealrelative to the frame, the seal includes a perimeter bead, ridge,projection and/or tongue that is received in and/or mates with a grooveand/or channel of the frame. The bead and corresponding groove mayinclude radiused corners to substantially reduce forces imparted on theseal. The seal may be positioned on a first side of the frame adjacentthe petals and/or a thrust reverser cover and on a second side of theframe adjacent the petals and/or the thrust reverser cover. The thrustreverser cover may cover at least a top portion of the seal and a bottomportion of the seal such that the seal is positioned between the frameand the thrust reverser cover on both the first and second sides of theframe. One or more fasteners (bolts, rivets, screws, etc.) may be usedto couple the thrust reverser cover, the seal and/or the frame together.

FIG. 1 illustrates an example aircraft 100 including jet engines 102 inaccordance with the teachings of this disclosure. In some examples, theengines 102 include sealed variable area fan nozzles (VAFN) 104 thatincrease fuel efficiency of the aircraft 100 by sealing and/orpreventing air leaks through movable petals of the VAFN 104.

FIG. 2 illustrates an example jet engine 200 in accordance with theteachings of this disclosure. The engine 200 includes a thrust reverser202 illustrated in a forward position 204 and a rearward position 206.In the forward position 204, air flows through the engine 200 between acore cowl 208 and an example thrust reverser cover 210. In the rearwardposition 206, air flows through apertures 212 of the thrust reverser202.

When in the forward position 204, to enable the engine 200 to adapt todifferent flight conditions, the engine 200 includes a VAFN 214including a plurality of petals 216 that are actuatable and/or movableto change (e.g., increase and/or decrease) the area between the corecowl 208 and the thrust reverser cover 210. In this example, the petals216 are positioned in an example seal assembly 218 that substantiallyseals and/or prevents leaks through the petals 216 to increase the fuelefficiency of the engine 200.

FIG. 3 is a partial cutaway view illustrating the example seal assembly218 including the VAFN 214 and enclosed therein. In the illustratedexample of FIG. 3, a portion of the seal assembly 218 has been removedfrom the figure to allow the petals 216 via brackets 325 of the VAFN 214position within the enclosed seal assembly 218 to be visualized. In thisexample, the VAFN 214 includes an actuation system, actuator, rodsand/or cables 302 coupled via brackets 325 to each of the petals 216 topivot the petals 216 about hinges 304 within the seal assembly 218 andincrease and/or decrease the area between the seal assembly 218 and thecore cowl 208. As shown in the illustrated example of FIG. 3, the rodsand/or cables 302 extend (e.g., movably extend) through the brackets 325to enable the rods and/or cables 302, when actuated, to cause the petals216 to taper outwardly relative to the hinges 304 to increase the areabetween the seal assembly 218 and the core cowl 208. Further, as shownin the illustrated example of FIG. 3, the rods and/or cables 302 extendthrough the brackets 325 to enable the rods and/or cables 302, whenactuated, to cause the petals 216 to taper inwardly relative to thehinges 304 to decrease the area between the seal assembly 218 and thecore cowl 208.

Referring to FIGS. 3-4, the example seal assembly 218 includes a frame306 to which a seal 308 is coupled, connected, linked, secured, orotherwise joined. The frame 306 may be made of any suitable materialsuch as, for example, Inco 625 Stainless Steel. The seal 308 may be madeof a single piece of material and/or multiple pieces of material (e.g.,an elastomeric seal material) having edges 310, 312 that define anopening 314 at a first end 316 of the seal assembly 218 and a foldedportion and/or fold 318 at a second end 320 of the seal assembly 218. Inoperation, the petals 216 move based on the flight condition and theseal 308 sealingly moves with the petals 216 substantially preventingairflow between the petals 216.

FIGS. 5-7 illustrate cross-sectional views of the example seal assembly218. As shown, the example frame 306 includes a first portion 502, asecond portion 504 and a third portion 506 positioned between the firstand second portions 502 and 504. In some examples, a first angle 520 isformed at an intersection between the first portion 502 and the thirdportion 506 and a second angle 522 is formed at an intersection betweenthe second portion 504 and the third portion 506. In some examples, thefirst angle 520 is different from the second angle 522. The firstportion 502 includes a first outer surface 508 adjacent and coupled to afirst inner surface 510 of the seal 308 and the second portion 504includes a second outer surface 512 adjacent and coupled to a secondinner surface 513 of the seal 308. The coupling between the frame 306and the seal 308 defines a chamber 514 into which the VAFN 214 is to bepositioned. The seal 308 includes a first panel 516 and a second panel518 that are folded about the folded portion 318.

FIGS. 6 and 7 illustrate an overlap 601 of a thrust reverser cover 602on the seal 308. Referring to FIG. 7, in some examples, the thrustreverser cover 602 includes a first inner surface 604 adjacent andcoupled to a first outer surface 606 of the seal 308 and the thrustreverser cover 602 includes a second inner surface 608 adjacent andcoupled to a second outer surface 610 of the seal 308.

FIG. 8 illustrates a coupling between the thrust reverser cover 602, theseal 308 and the frame 306. In this example, a fastener 802 extendsthrough the thrust reverser cover 602, the seal 308 and the frame 306 tocouple the components 602, 306, 308 together. Additionally, in thisexample, the frame 306 defines a groove 804 that receives a projection(e.g., a perimeter projection) 806 of the seal 308 to couple the seal308 and the frame 306 together.

FIG. 9 illustrates another view of the groove 804 of the frame 306receiving the projection 806 of seal 308.

FIG. 10 illustrates an isometric view of the frame 306. The frame 306includes a first leg or portion 1002, a curved or second portion 1004and a second leg or third portion 1006. The legs 1002 and 1006 extendfrom respective ends 1008, 1010 of the curved portion 1004. In thisexample, the portions 502, 504 on the legs 1002, 1006 converge at and/ortaper toward respective ends 1012, 1014.

The legs 1002, 1006 and the curved portion 1004 include and/or defineopposing grooves 804 that receive the projection 806 of the seal 308.While the grooves 804 adjacent the ends 1008, 1010 are depicted asincluding approximately 90-degree corners, in other examples, thegrooves 804 adjacent the ends 1008, 1010 may be curved and/or radiused(e.g., a two-inch radius).

FIG. 11 illustrates the seal 308 including the first panel 516 and thesecond panel 518. The panels 516, 518 are spaced adjacent the opening314 to enable the curved portion 1004 of the frame 306 to be receivedtherein. In this example, the seal 308 includes a central curved portion1102 in which the petals 216 may be positioned and portions and/orextensions 1104 to receive the legs 1002, 1006. In the regard, the sealassembly 218, that is, the frame 306 and seal 308, and the variable areafan nozzle petal actuation system 104 may be correspondingly shaped.

FIG. 12 illustrates the projection(s) 806 on the seal 308. While theprojection 806 is illustrated as including substantially non-radiusedcorners 1202, 1204, the corners 1202, 1204 may be curved and/orradiused.

As set forth herein, an example apparatus includes a frame and a seal tobe coupled to the frame. The seal is to enclose petals of a variablearea fan nozzle to substantially prevent airflow between the petals. Insome examples, the seal includes a projection and the frame includes agroove to receive the projection. In some examples, the seal includesopposing inner surfaces. The opposing inner surfaces are to bepositioned adjacent opposing outer surfaces of the frame. In someexamples, the frame includes a first portion, a second portion, and athird portion. The second portion is positioned between the first andthird portions.

In some examples, the first portion and the third portion includegrooves to receive a projection of the seal. In some examples, thesecond portion is substantially perpendicular relative to a longitudinalaxis of the variable area fan nozzle. In some examples, the firstportion includes a first angle relative to the longitudinal axis of thevariable area fan nozzle and the third portion includes a second anglerelative to the longitudinal axis of the variable area fan nozzle. Thefirst angle is different than the second angle. In some examples, theframe includes a first portion, a curved portion, and a second portion.The first portion is to extend from a first end of the curved portion.The second portion is to extend from a second end of the curved portion.

In some examples, the seal includes a single-piece of material. In someexamples, the seal includes a first end and a second end. The first endcomprising an opening to receive the frame, the second end to comprise afold. In some examples, the frame includes urethane to interface withthe seal. The urethane to substantially reduce damage of the seal basedon interaction with the frame.

Another example apparatus includes a thrust reverser cover having avariable area fan nozzle. The apparatus includes a seal assembly toenclose petals of the variable area fan nozzle to substantially preventairflow between the petals. In some examples, the seal assembly includesa frame and a seal to be coupled to the frame. The seal to enclose thepetals of the variable area fan nozzle. In some examples, the sealincludes a projection and the frame includes a groove to receive theprojection.

In some examples, the seal includes opposing inner surfaces. Therespective inner surfaces are to be positioned adjacent respectiveopposing outer surfaces of the frame. In some examples, the frameincludes a first portion, a second portion, and a third portion. Thesecond portion is positioned between the first and third portions. Insome examples, the frame includes a first portion, a curved portion, anda second portion, the first portion to extend from a first end of thecurved portion, the second portion portion to extend from a second endof the curved portion. In some examples, the seal includes asingle-piece of material. In some examples, the seal includes a firstend and a second end. The first end includes an opening to receive theframe. The second end is to include a fold.

An example method to enhance the operation of a variable area fan nozzleincludes using a seal fabricated from a piece of material that mates toa structure and forms a rigid outer edge along a perimeter of thematerial and allows the piece of material to overlap the structure.

Furthermore, although certain example methods, apparatus and articles ofmanufacture have been described herein, the scope of coverage of thispatent is not limited thereto. On the contrary, this patent covers allmethods, apparatus and articles of manufacture fairly falling within thescope of the appended claims either literally or under the doctrine ofequivalents.

What is claimed is:
 1. An aircraft engine comprising: a variable areafan nozzle including a plurality of petals; and a seal assemblyincluding: a frame; and a seal coupled to the frame such that a chamberis formed between the seal and the frame, the plurality of petalscoupled to the frame and disposed within the chamber.
 2. The aircraftengine of claim 1, wherein the seal includes a first panel and a secondpanel, the first and second panels having fore edges that are spacedapart from each other and aft edges that are coupled to each other. 3.The aircraft engine of claim 2, wherein the frame includes an outerradial wall and an inner radial wall, the first and second panelscoupled to the outer and inner radial walls, respectively, at or nearthe fore edges of the first and second panels.
 4. The aircraft engine ofclaim 3, wherein an inner surface of the first panel is coupled to anouter surface of the outer radial wall, and an inner surface of thesecond panel is coupled to an outer surface of the inner radial wall,such that the frame is disposed between the first and second panels. 5.The aircraft engine of claim 4, further including a thrust reversercover, wherein the seal assembly is coupled to the thrust reversercover.
 6. The aircraft engine of claim 5, wherein the thrust reversercover includes an outer wall and an inner wall, the seal assemblycoupled between the outer wall and the inner wall of the thrustreverser, the first panel of the seal disposed between the outer wall ofthe thrust reverser cover and the outer radial wall of the frame, andthe second panel of the seal disposed between the inner wall of thethrust reverser cover and the inner radial wall of the frame.
 7. Theaircraft engine of claim 5, further including a fastener extendingthrough the thrust reverser cover, the seal, and the frame to couple thethrust reverser cover, the seal, and the frame.
 8. The aircraft engineof claim 2, wherein the chamber has a tapered cross-section thatdecreases in height from the fore edges of the first and second panelsto the aft edges of the first and second panels.
 9. The aircraft engineof claim 2, wherein the aircraft engine includes a core cowl, andwherein the second panel is disposed between the plurality of petals andthe core cowl.
 10. The aircraft engine of claim 1, wherein the frameincludes a curved portion, a first leg extending rearward from a firstend of the curved portion, and a second leg extending rearward from asecond end of the curved portion.
 11. The aircraft engine of claim 10,wherein the frame includes a first groove extending along an outersurface of the curve portion, the first leg, and the second leg, and theframe includes a second groove extending along an inner surface of thecurved portion, the first leg, and the second leg.
 12. The aircraftengine of claim 11, wherein the seal includes a first panel with aninner surface having a first projection to mate with the first grooveand a second panel with an inner surface having a second projection tomate with the second groove.
 13. The aircraft engine of claim 1, whereinthe seal is constructed of an elastomeric material to enable the seal toflex as the petals expand or contract in the chamber.
 14. The aircraftengine of claim 1, wherein the variable area fan nozzle includes anactuation system to move the petals, the actuation system disposedwithin the chamber.
 15. A seal assembly comprising: a frame having anouter radial wall, an inner radial wall spaced apart from the outerradial wall, and a middle wall between the outer radial wall and theinner radial wall; and a seal coupled to the frame, the seal including afirst panel coupled to the outer radial wall and a second panel coupledto the inner radial wall, the first panel coupled to the second panel ataft edges of the first and second panels, the frame, the first panel,and the second panel forming a wedge-shaped chamber to enclose avariable area fan nozzle.
 16. The seal assembly of claim 15, wherein thefirst panel includes a first projection extending from an inner surfaceof the first panel and the outer radial wall includes a first groove,the first projection disposed within the first groove.
 17. The sealassembly of claim 16, wherein the second panel includes a secondprojection extending from an inner surface of the second panel and theinner radial wall includes a second groove, the second projectiondisposed within the second groove.
 18. The seal assembly of claim 15,wherein the frame includes a curved portion, a first leg extendingrearward from a first end of the curved portion, and a second legextending rearward from a second end of the curved portion.
 19. The sealassembly of claim 15, wherein the frame includes urethane to reducedamage to the seal from an interface between the seal and the frame. 20.The seal assembly of claim 15, wherein the seal is constructed of asingle piece of material.